Cold hardiness & minimum temperature

Is Drooping Spleenwort (Asplenium flaccidum)cold hardy? Hardiness zone & min temp

Also called Drooping Spleenwort, Weeping Spleenwort.

More about drooping spleenwort

About Drooping Spleenwort

Asplenium flaccidum · also called Drooping Spleenwort, Weeping Spleenwort · houseplant

Asplenium flaccidum is a graceful, pendulous fern native to New Zealand, Australia, and the Pacific, producing soft, drooping pinnate fronds that hang elegantly — ideal for hanging baskets or elevated shelves. As an epiphytic or lithophytic species it is adapted to excellent drainage and good air movement. It suits humid, cool-to-intermediate indoor spaces.

Cold limit: USDA 8-10 · RHS H3 (8–22°C)

Watch for — Sluggish growth in winter: Growth slows markedly in cool, low-light winter conditions. This is natural. Reduce watering frequency and stop feeding until spring. Providing supplemental grow lighting in winter can maintain moderate growth through the season.

What drooping spleenwort's hardiness rating actually means

Drooping Spleenwort is half-hardy (RHS H3). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Its RHS rating of H3 means: Half-hardy — comes through mild UK winters outside but is killed by a hard freeze. On the US scale that maps to USDA 8-10 — the zones where it can be left outdoors year-round.

New to these scales? The USDA hardiness zone map explained covers how the zone numbers work, and you can find your own zone with the zone finder.

Minimum temperature — and what happens below it

Minimum survivable temperature is roughly about −5 to 1 °C — a light, short frost only. Drooping Spleenwort shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for drooping spleenwort as it gets too cold:

Down to roughly about −5 to 1 °C it copes, especially if dry and sheltered.
A sustained hard frost collapses the top growth; whether it returns depends on whether the roots, crown or tubers froze.
Wet cold is far more lethal than dry cold for this plant — soggy, frozen soil is the usual killer.

Can drooping spleenwort go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 8-10 or a frost-free UK microclimate.
In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter.
A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

Work back from your local frost dates with the frost-date calculator: the last spring frost and first autumn frost are what really decide when drooping spleenwort can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H3 figure above.

Frost protection for borderline drooping spleenwort

Drooping Spleenwort is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost.
Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse.
Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones.
Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.

Drooping Spleenwort hardiness — frequently asked questions

Is drooping spleenwort cold hardy?

Drooping Spleenwort is half-hardy (RHS H3). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Borderline outdoors. In its mild end of USDA 8-10 (and sheltered UK gardens) drooping spleenwort can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature drooping spleenwort can survive?

Minimum survivable temperature is roughly about −5 to 1 °C — a light, short frost only. Drooping Spleenwort shrugs off cold nights but a real, sustained freeze will kill it.

What hardiness zone is drooping spleenwort?

Drooping Spleenwort is rated USDA 8-10 and RHS H3 — Half-hardy — comes through mild UK winters outside but is killed by a hard freeze.

Can drooping spleenwort survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 8-10 or a frost-free UK microclimate. In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter. A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

How do I protect drooping spleenwort from frost?

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost. Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse. Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones. Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.